> For the complete documentation index, see [llms.txt](https://docs.shardspace.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.shardspace.app/trading/limit-order-trades/the-limit-order-page/the-order-book.md).

# The Order Book

The order book is one of the key features of a limit order exchange, it shows you what orders exist on AlphaDex.

Because AlphaDex provides the back-end DEX functionality for many front-end exchanges (like ShardSpace) the order book you see shows all the orders existing on AlphaDex and not just those submitted on ShardSpace. When you place either a buy order (in green) below the market 'Price' or a sell order (in red) above the market 'Price' it will get added to the order book. If you submit a buy order above the market price or sell order below the market price these are normally executed asap and are usually not added to the order book. Liquidity depending.

<figure><img src="https://3349340751-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fle7VWa5Gdik0R7Zu5KMm%2Fuploads%2FS5ODAIuVDWDzzS9oJz04%2Fimage.png?alt=media&amp;token=bad6dd52-835f-4111-8cfb-77a7ed154255" alt="" width="540"><figcaption></figcaption></figure>